查询词典 mode of vibration

Based on the analysis for the dynamic characteristics of semi-rigid steel frames with simple or multiple degree-of-freedoms,effects of rotation stiffness of beam-to-column connections on the structure period,frequency,critical damping and mode of vibration are discussed.

通过对单自由度体系和多自由度体系半刚接钢框架的动力特征分析，初步探讨了梁柱连接转动刚度对结构自振周期、频率、临界阻尼以及振型等参数的影响。

In the past, the high frequency resonance technique is usually applied in the envelope detection for a vibration signal with amplitude modulation. When applying the Hilbert transform in the high frequency resonance technique for the envelope detection of vibration signals, the computing burden is very high. On the other hand, when applying the linear least squares analysis method, the computing burden is lower. When applying the envelope detection in the lowest vibration mode, an accelerometer with the low-pass filtering cutoff frequency at 4kHz should be choose.

在过去的研究方法中，振动讯号之振幅调变通常以高频解调分析法应用於包络讯号侦测，而高频解调方法应用希尔伯特转换的包络分析，所需要的计算量是非常的高，若以线性最小平方分析法应用於高频解调分析法中，则所需要的计算量较小，如果以最低模态来估测包络讯号时，可以适当的选取加速规来代替低通滤波器，而加速规的截止频带必须在4kHz左右。

Also, the characteristics of the lower order frequencies and the lower order mode of vibration are found out.

模态分析是动力学计算的基础，为动力学分析计算提供了必要的模态参数。

It is found that the changes in the mode of vibration are sensitive to the damage degree of elements, and there exists a corresponding relationship between them.

发现振动模态的变化对单元损伤的程度较为敏感且有对应关系。

Localization is able to destroy the regularity of mode of vibration in periodic structure and aberration of vibration mode occurs.

若周期结构的整体结构尺寸不是很大，那么振动模态不会遍及整个结构，出现振动局部化现象。

The free vibration of a nonlinear elastic rectangular plate is explored, considering influence of material nonlinearity and static-load in plane on its dynamic characteristics. Exact solution to free vibration of each mode of the rectangular plate is obtained according to the fixed point theory of partially ordered space. So the whole process of free vibration is described.

对非线性弹性矩形板的自由振动进行了研究，考虑了材料非线性和面内静载对板动力特性的影响，并根据半序空间的不动点理论求得该矩形板在自由振动时各阶模态的精确解，描绘了其自由振动的全过程。

In this topic, the dynamic analysis methods for piezoelectric vibrator are studied systematically based on the theoretical model, FEM numerical experimentation and FEM governing equation for given compound-mode vibrator, and some valuable conclusions are obtained. The main work accomplished is summarized as follows: 1.Elaborate the main modeling methods for piezoelectric vibrator and the significance and necessity to study the dynamic characteristics of piezoelectric vibrator which emphasize the urgency of this paper. 2.Take the bending deformation induced by piezoelectric ceramic as example, the energy transfer mechanism of electric energy to mechanical energy are analyzed; the motion and force transfer mechanism are analyzed for the longitudinal-bending vibrator. 3.Based on mode assumption and Hamilton principle, the coupling model of piezoelectric vibrator of linear USM is built; moreover, the equivalent circuit model is obtained and a coupling equation represents the relation between electric parameters and mechanical parameters is derived which provides foundation to match the vibrator and driving circuit. 4.Combine the constitutive equation of piezoelectric ceramic with elastic-dynamical equation, geometric equation in force field and the Maxwell equation in electric field and the corresponding boundary condition equation, the FEM control equation for piezoelectric vibrator of USM to solve dynamic electro-mechanical coupling field is established by employing the principle of virtual displacement. The equation lays the foundation to study the non-linear constitutive equation of piezoelectric ceramic driven by high-power. 5.Define the dynamic indexes of characteristic of vibrator and carry out variable parameters simulation by calculating the model parameters and the electric characteristics of vibrator are simulated according to the equivalent circuit model. By numerical experimentation, the working mode of vibration of vibrator and the shock excitation results of the working frequency band which provides the mode frequency to realize bimodal are analyzed. Detailed calculation of the electro-mechanical coupling field parameters is made by programming the FEM control equation.

本课题从理论模型、有限元数值试验、有限元控制模型等方面以复合振动模式振子为例对超声电机压电振子的动力学特性及其分析方法进行了全面系统地研究，得出了许多有价值的结论，主要概括如下： 1、阐述了目前针对超声电机压电振子的主要建模方法，对压电振子动态特性的研究意义和必要性进行了论述，突出了本文研究内容的迫切性； 2、以压电陶瓷诱发弹性体发生弯曲变形为例，分析了压电陶瓷通过诱发应变来实现机电能量转换的机理；对基于纵弯模式的压电振子的运动及动力传递机理进行了分析； 3、基于模态假定，利用分析动力学的Hamilton原理，建立了面向直线超声电机压电振子的机电耦合动力学模型，并据此建立了压电振子的等效电路模型，导出了电参量与动力学特性参量的耦合方程，为压电振子与驱动电路的匹配提供了依据； 4、从压电陶瓷的本构方程出发，综合力场的弹性动力学方程、几何方程、电场的麦克斯韦方程以及相应的边界条件方程，采用虚位移原理，建立了压电振子动态问题机电耦合场求解的有限元控制方程，为研究其大功率驱动下的非线性本构模型奠定了基础； 5、界定压电振子的动力学特性指标，对压电振子的机电耦合动力学模型参数进行计算及变参数仿真；依据等效电路模型，对压电振子的电学特性进行了仿真分析；通过有限元数值实验，对压电振子工作模态附近的模态振型及工作频率附近的频段进行了激振效果分析，找出了实现模态简并的激振频率；利用有限元控制方程，通过编程计算，对压电振子的力电耦合场参数进行了详细计算，得出了一些有价值的结论。

For vibration mode-shape, this affect is moreseverity on high rank stage vibration than low. With opened hollow and pier added on dam,the frequency of vibration decline.

对于振型而言，这种影响对低阶振型比高阶振型大，考虑孔口和闸墩后，大坝的自振频率有所降低；在低阶振型中有一部分的排列顺序发生了变化，但这些变化不致使大坝的动力特性发生显著的改变。

ChapterⅢ,system model of chapter II was simplified as the free vibrationmodel of the system to solve the inherent vibration frequency and vibration mode.The inherent vibration modes are divided into three categories:torsional vibrationmode of central component,translational and torsion pendulum vibration mode of thecenter component and planetary gear vibration mode.

第三章对第二章建立的系统模型简化为自由振动模型，求解了系统的固有振动频率及振型，将各工况下的固有振型分为三类：中心构件扭转振动模式、中心构件平移扭摆振动模式和行星轮振动模式。

Besides,the infrared and Ramam activity of the vibration mode of the molecule and some possible transition of the vibration spectrum has also been researched.The results show: the vibration mode of Cr6 molecule is Гvib=2A1g+2E...

研究结果表明，其振动模式是红外活性，振动模式A1g、Eg和T2g是拉曼活性，振动模式T1g和T2u是非活性的，红外跃迁可以跃迁到T1u，拉曼跃迁可以跃迁到A1g、Eg和T2g。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。